While I agree with the above statement (and some of your others), they didn't buy the devices. It was a developer preview provided to them under NDA. I think iFixit is clearly in the wrong here.
From the article:
The developer unit we disassembled was sent to us by Apple. Evidently, they didn’t intend for us to take it apart. But we’re a teardown and repair company; teardowns are in our DNA—and nothing makes us happier than figuring out what makes these gadgets tick. We weighed the risks, blithely tossed those risks over our shoulder, and tore down the Apple TV anyway.